Have you ever noticed that people on diets are really crabby? While many might blame low blood sugar or a general lack of pleasure (rice cakes, cabbage soup — ugh!), recent psychological research suggests that it’s actually the exercise of self-control that leads people to become irritable and aggressive at inappropriate times.
The prevailing theory is that because self-control is a finite resource, when you deplete it — say by consistently choosing carrots over cupcakes or by refraining from splurging at the shoe store — you’re less likely to be able to control urges toward anger or aggression when they arise at inappropriate times.
“Research has shown that exerting self-control makes people more likely to behave aggressively toward others, and people on diets are known to be irritable and quick to anger,” said researchers David Gal, an assistant professor of marketing at the Kellogg School of Management at Northwestern University, and Wendy Liu, an assistant professor of marketing at the Rady School of Management at the University of California San Diego, in a statement. (More on Time.com: Health-Washing: Is ‘Healthy’ Fast Food for Real?)
Now in a new study, the marketing professors further explore the association between self-control and anger, and find that the two may linked in a broader way: in their study, people who exerted self-control showed anger-related behaviors even in situations in which they weren’t inappropriate and, thus, wouldn’t necessarily have to be snuffed out.
In a series of three experiments, the researchers asked study participants to exercise self-control in various ways, then measured their tendency to make aggressive or anger-related choices. In the first experiment, participants were asked to choose between two snacks — an apple or a chocolate bar — before choosing a movie to watch. (Another group chose the movie first, then were given a snack choice after watching.)
Among those who made the good-for-you initial choice (the low-calorie, high-fiber apple), 64% subsequently opted to watch a movie with aggressive themes, like Anger Management (over Billy Madison) or Hamlet (over Romeo and Juliet). By contrast, 55% of those who did not have to choose a snack before the film picked an anger-themed movie. As for the people who got chocolate — either before or after the film — they chose anger-themed movies at the same rate.
Dieting isn’t the only form of self-control that may cause aggression. In another experiment, a group of 139 women were randomly assigned to choose between a $50 gift certificate for a spa treatment (the indulgent, enjoyable choice) or for groceries (the responsible option) either before or after rating a series of six photographs of angry or fearful faces. (More on Time.com: Calorie Counts on Menus: Apparently, Nobody Cares)
The women who chose the gift certificate for groceries before rating the faces gave the angry faces a score of 3.75 (based on a 1-to-7 scale, where 1 is “not arousing” and 7 is “extremely arousing”); the group who selected groceries after rating faces gave the angry faces a score of 3.12 score. There was no difference in angry-face scores among the participants who chose the spa treatment.
In the final experiment, participants were again asked to choose between an apple or a candy bar either before or after reading a message that suggested exercise by using controlling words like “should,” “ought,” “must” and “need to.” As expected, the people who chose an apple before reading the health messages were more likely to rate them as irritating.
“Given that most individuals are frequently engaged in self-regulation throughout any given day — whether it be resisting the urge to mock one’s boss, to yell at a screaming
baby, to eat an extra slice of chocolate cake, to save instead of spend, or to play instead of work — our ﬁndings suggest that anger-related behavior might be more prevalent than previously assumed or reported,” the researchers wrote. (More on Time.com: Diet Soda May Lead to Stroke Risk? Really?)
They also described some interesting marketing implications, suggesting, for example, that anger-themed movies and video games (like the mobile video game “Angry Birds”) would do well to advertise in health-food aisles of grocery stores and other places where people do their best to exert self-control.
For policy makers, the authors suggest they remain mindful of the emotional consequences on the consumer of public-service admonitions to eat healthily or save for retirement, and try using more positive ways to persuade people to behave responsibly.
As for the angry, self-deprived consumer herself, the authors’ best advice involves “avoiding self-control dilemmas in the first place or cognitively reappraising the situation so that the virtuous choice does not involve a denial of satisfaction.” Try as you might to convince yourself, though, no apple is likely to satisfy you, if what you really want is a Hershey bar. So go ahead and splurge once in a while.